Perhaps you're upgrading to a newer iPad and you really like your case or you want to adapt a cheap 1st-gen iPad case to your Android tablet. Either way you can adjust for size differences and add camera and port access holes when needed by using a small precision drill such as that found on a rotary tool.

Design weblog Apartment Therapy points out that the old adage "measure twice, cut once" applies here. You'll want to measure where you need to make a hole for your camera or headphone jack, draw the hole on the case, and drill the hole. Trim around the hole with a small pair of scissors and if you want a more finished look you can use bias tape, needle and thread, or Mod Podge glue.